HL7800 wakeup from eDRX timing

IoT Modules HL78
1

Hi,
We’re using HL7800, FW: BHL78XX.3.4.1.0 in our application utilizing a NB-IoT network. The modem is mostly in eDRX mode, but needs to periodically wake up in order to send UDP-data.
I’ve noticed that if I try to open an UDP-session with to short delay after waking the modem up the modem just responds with “ERROR”.
How can I make sure that the modem is ready for “AT+KUDPCFG” commands?
As of now I’ve tried to wait until the modem responds to the “AT”-command with an “OK” and also responds to “AT+CREG?”-command, but it is not sufficient.

At-log (ms - command):
126588 - AT
126588 -
126588 - OK
126668 - AT+CREG?
126668 -
126668 - +CREG: 0,5
126668 -
126668 - OK
126757 - AT+KUDPCFG=1,0
126757 -
126757 - ERROR
126846 - AT+KUDPCFG?
126846 -
126846 - ERROR
126936 - AT+KUDPCFG=1,0
126936 -
126936 - ERROR
127031 - AT+KUDPCFG?
127031 -
127031 - ERROR

–EDIT:–
It also appears to affect commands other than the AT+KUDPCFG.
This is from my init sequence:
9249 - AT
9249 -
9249 - OK
7925 - AT+CFUN=0,0
7925 -
7925 - OK
8026 - AT+CEDRXS=1,5,2
9007 -
9007 - OK
9027 - AT+KRIC=128,0,5,2
9027 -
9027 - ERROR
9124 - AT+KSLEEP=1,1,2
9124 -
9124 - ERROR

The CFUN and CEDRXS commands are accepted but the KRIC and KSLEEP are not.

–END EDIT–

Thanks in advance
Martin

2

Hi,

I suppose you may missed the APN settings.

PLease try the following sequence:
ATI3
ATE1
AT&W
AT+KSLEEP?
AT+COPS?
AT+CEDRXS=1,5,2
AT+CEDRXRDP
AT+KRIC=128,0,1,2
AT+KSLEEP=1,2,10
AT+KCNXCFG=1,“GPRS”,“CMIOT”
AT+KUDPCFG=1,1,5555,0,"",0,0,1
AT+KUDPSND=1,“xx.xx.xx.xx”,5021,5
AAAAA–EOF–Pattern–
AT+KUDPCLOSE=1,1
AT+KUDPDEL=1

3

Hi,
I didn’t post the entire init sequence because I face no problem there.
The APN settings are fine.

The problem is as follows:
If I execute the command AT+KUDPCFG with a too short delay from waking the device from eDRX (by pulling the WAKE_UP pin), the modem replies with “ERROR”.
If I wait longer, lets say 10 seconds, the modem replies with “OK”.

How can I make sure that the modem is ready for this command (AT+KUDPCFG) after waking it up?

Thanks
Martin

4

It’s about 3 seconds for a warm boot.
So, please send AT at least 3 seconds after wake up by pulling WAKE_UP pin.